Measurement-Based Spatially Explicit Methane Emission Inventory (EI-ME)

Accurate and comprehensive assessment of methane emissions, a powerful climate warming pollutant, is a key first step in reducing these emissions, while supporting the ability to track progress toward such reductions over time. While national bottom-up source-level inventories are useful for understanding the sources of methane emissions, they are often unrepresentative across spatial scales, adn their reliance on generic emission factors produces underestimations when compared with measurement-based inventories.

In this work, we compile and analyze previous peer-reviewed measurement-based data on facility-level methane emissions in the US oil and gas sector and use these data to develop statistically robust emissions models from which we estimate total methane emissions for the population of major US oil and gas facilities.

This dataset (EI_ME_v1.0.gpkg) aggregates the results of this measurement-based methane emission inventory (EI-ME), which is focused on oil and gas methane emissions in the US onshore production regions. The emissions estimates are spatially resolved at 0.1 x 0.1 degree spatial scales.

The data layers in the GeoPackage are:

• EI-ME_gridded_ch4_emissions: estimated methane emissions, spatially resolved at 0.1x0.1 degree spatial grids
• EI-ME_US_oil_gas_basins: major US oil and gas basin boundaries, based on EIA basin boundary definitions.
• EI-ME_facility_ch4_measurements_data: A compilation of previous peer-reviewed facility-level measurement-based data for oil and gas methane emissions in the US.

We also provide a netcdf version ("EI_ME_2021_inventory_CONUS_point1_degrees_v1.nc") which includes estimated mean oil and gas methane emissions over the contiguous US (excludes Alaska) aggregated over a slightly offset spatial grid compared to the full domain in the above .gpkg.

Complete details of the emissions model development and dataset creation can be found in the following manuscript:

• How to cite: Omara, M., Himmelberger, A., MacKay, K., Williams, J. P., Benmergui, J., Sargent, M., Wofsy, S. C., and Gautam, R.: Constructing a measurement-based spatially explicit inventory of US oil and gas methane emissions, Earth Syst. Sci. Data Discuss. [preprint], https://doi.org/10.5194/essd-2024-72, in review, 2024.

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Contact at Environmental Defense Fund: Mark Omara (momara@edf.org)

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